1. Field of the Invention
The invention relates to an energy-absorbing device, in particular in the form of safety device against shock loads for a track-borne vehicle, the energy-absorbing device having an energy-absorbing member and a mating member which co-operates with the energy-absorbing member in such a way that, if a critical shock force applied to the energy-absorbing device is exceeded, the mating member and the energy-absorbing member move relative to one another, towards one another, while at the same time absorbing at least some of the shock energy which is applied to the energy-absorbing device.
2. Prior Art
It is known for track-borne vehicles, such as rail-borne vehicles for example, to be fitted with a safety device against shock loads which has at least one energy-absorbing device the purpose of which is to at least partly dissipate the shock energy which occurs if the vehicles hits an obstacle. An energy-absorbing device which is used in a safety device against shock loads generally has one or more energy-absorbing members. The intention in this case is that the at least one energy-absorbing member, which is generally designed to be destroyed, will protect the main frame of the track-borne vehicles even when, in particular, the closing speeds are quite high.
Energy-absorbing devices designed to be destroyed which are known from the prior art are in particular deformation tubes or crash boxes in which shock energy is destructively converted into work done in deformation and heat by a defined plastic deformation.
Printed publication DE 297 03 351 U1, for example, relates to a member for absorbing kinetic energy, this member operating mechanically on the principle of plastic deformation. Specifically, what is proposed in this piece of prior art is an energy-absorbing device which has a base-plate and a connecting plate, with an energy-absorbing member being clamped between these two plates. The energy-absorbing member is a thick-walled tube of plastics material which on the one hand has a certain initial elasticity and on the other hand has a plastic working travel for which the stress-strain curve is almost rectangular plastic. The initial elasticity of the energy-absorbing member gives protection by deformation when the shock loads are low. After a working travel beyond the yield point, plastic deformation of the energy-absorbing member occurs, and consequently the energy-absorbing member is reduced in length and its outer circumference is enlarged in a bulged shape.
What is known from printed publication WO 2009/034123 A1 on the other hand is a safety device against shock loads which is particularly suitable for use, together with a component for transmitting force, as an additional, irreversible stage for providing safety against shock loads. This safety device against shock loads has an energy-absorbing member in the form of a deformation tube and a mating member in the form of a force-transmitting member. The mating member (force-transmitting member) co-operates in this case with the energy-absorbing member in such a way that, on a characteristic shock force which can be laid down in advance being exceeded, the energy-absorbing member in the form of a deformation tube is deformed plastically and in the process dissipates at least some of the energy which arises when the shock force is transmitted. In the course of the plastic deformation of the deformation tube the deformation tube (energy-absorbing member) and the force-transmitting member (mating member) move relative to one another, towards one another.